We saw it about two months ago after applying one of the MS patches or
hotfixes. We tracked it down to a registry setting that caused the machine
(both workstations and servers) to do an LDAP refresh or something, every 2
hours. The default was to check every 12 hours.
I'm guessing that doing the repair rolled some of the settings back to the
default settings - could be that's what resolved it for you.